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Hot Exhaust


NAXJA Forum User
Kent, WA
I am from the KC area and took a trip out to CO to enjoy the mountain trails last week. While climbing up Red Cone Pass I banged my muffler on a rock ledge. It didn't do any noticeable major damage, just some dents and no punctures so I didn't think much of it. On the way back to KC this week, the exhaust apparently got so hot right at the muffler that it melted the carpet and floor mat just in front of the back seat.

I have heard of catalytic converters getting red hot when they are clogged, but I haven't heard of mufflers getting clogged. I have beaten other mufflers much worse than this without this type of problem.

Has anyone else experienced anything like this? Could I have knocked something loose in the muffler and clogged it up? Would a clogged muffler get hot enough to burn about a palm sized spot in the carpet? Could my catalytic converter be clogged and build up this much heat? Should I just replace the muffler and catalytic converter?

Thanks for any help,
Never have i heard of a muffler getting that hot. Did it knock it up closer to the underside by some chance?? Or, did it knock a crack in the top to where the exhaust is pouring out onto that part of the truck? It could be that it did knock the substate loose in the cat to where it is getting to hot, maybe localized and the heat is concentrataing at that point? Does not normally happen that way, but maybe can sometimes.

If the cat was hit hard or/and substantially dented there was damage to the ceramic honeycomb. It really is quite brittle. When broken it does tend to break to pieces disrupting efficient flow but usually is noticable performance wise too- I would not necessarily replace the muffler if not leaking, but scrutinize the cat.
I second the "bending" thought -- not too uncomon...

Check for clearances, prolly just "shortened" the air space between the Muffler and floor...

... Not that it helps you now, but a few of those "air bake" cookie sheets, or just a few thin metal plates with space held between them (think aluminum sheets riveted together using washers for spacers - mounted to the pan with spacers...) are quite effective at keeping the floor safe from thermal assaults
It doesn't appear to be any closer to the floor and it is still intact on the top. There are actually no holes anywhere in it, just a couple of dents.

The catalytic converter was not dented at all, just the muffler. Is the ceramic honeycomb brittle enough to be damaged by a hit to the muffler?

Hey I have no idea about the ehaust but you said that you were from Prairie Vill?? Im from Lenexa! I was wondering if you were at the Lenexa Barbque? Is your Jeep black? Just wondering bc I think I might have seen your Jeep!

No, mine is a dark green Country with the ends chopped off the front bumper.
Really the cat should be able to withstand a little abuse -- though they do shatter or burn occaisionally -- any possibility that your cat has blown? (you should be able to tell by whapping the bottom of your muffler and cat... neither should sound like maracas (sorry Charro, no coochie coochie for you!)
I will check it and see if anything sounds odd.

i have a problem whith my exhaust glowing red at the headers. the exhaust got so hot it melted my rino lining and started a fire. i have no cat and zero back pressure can someone help?
Roadcone said:
i have a problem whith my exhaust glowing red at the headers. the exhaust got so hot it melted my rino lining and started a fire. i have no cat and zero back pressure can someone help?

First suspect for redhot manifolds is retarded timing. Did you modify the cam? If so, check the valve timing.
dude, you started a thread in mod tech that's getting answers, and you've dug up two old ones.
posting the same question in more than one place is not an effective way to resolve the problem.
I appluad you for searching, but stop brining up 2 year old threads when you've got an active one in mod tech already. It's kind of annoying.